1. Technical Field
The present invention relates to a lighter that employs an ignition system which presents increased difficulty of operation by unintended users.
2. Background Art
Disposable gas lighters are available in a variety of forms. One common element of disposable lighters is an actuator pad or lever used to initiate the flow of fuel. An actuator pad is operated in conjunction with a spark producing mechanism so that the flow of fuel is ignited soon after it commences. For example, lighters employing conventional spark wheels require a user to rotate a toothed spark wheel against a flint in order to generate a spark. The user then depresses the actuator pad, to release gas and produce a flame.
Another means of ignition for disposable lighters employs a piezoelectric mechanism. In this type of ignition mechanism, a piezoelectric element, such as a crystal, is struck by a plexor in order to produce an electric spark. The spark is conducted to a location near the opening of the valve to ignite the gaseous fuel. The actuator pad, upon forced depression by a user, commences both the flow of the fuel and the ignition process. An example of such a piezoelectric ignition mechanism is disclosed in U.S. Pat. No. 5,262,697, entitled xe2x80x9cPiezoelectric Mechanism For Gas Lighters.xe2x80x9d
As with spark wheel ignition mechanisms, measures have been introduced to increase the difficulty of activation to inhibit unintended activation of piezoelectric mechanisms or activation by unintended users (e.g., children younger than five years of age). One typical method is to incorporate a separate latch member disposed under the actuator pad, which inhibits depression of the actuator pad. Examples of such mechanisms are shown in U.S. Pat. Nos. 5,435,719, 5,584,682, and 5,636,979.
There remains, however, a need in the art for other mechanisms, which increase the difficulty of unintentional operation or operation by unintended users, and at the same time are user-friendly for intentional operation by intended users.
According to the present invention a lighter resistant to use by unintended users is disclosed. The lighter comprises a housing with a fuel supply and a blocking surface, a valve for controlling the release of fuel from the fuel supply, an actuator, an ignition mechanism, and a latch member. The actuator is mounted for movement with respect to the housing from a first position to an actuation position. The ignition mechanism is coupled to the actuator, and the actuator is movable from the first position to the actuation position along a longitudinal, actuation axis. This movement of the actuator allows the ignition mechanism to ignite the fuel. The latch member is pivotally or slidably coupled to the actuator. The latch member includes a finger actuation portion and a body portion with a blocking or free end.
When the latch member is in the first position, the blocking end of the body portion of the latch member is aligned with the blocking surface of the housing to prevent actuation of the lighter by limiting the movement of the actuator along the actuation axis. When the latch member is pivotally coupled to the actuator, moving the finger actuation portion of the latch member in a first direction causes the blocking end of the body portion to move in a second direction substantially opposite the first direction. This also causes the blocking end of the latch member to become unaligned with the blocking surface of the housing. This unalignment is the intermediate or unlocked position. This permits movement of the actuator from the first position to the actuation position to actuate the lighter. In one embodiment, during the movement of the latch toward the intermediate position, the finger actuation portion moves in the first direction, which is substantially forward, and the blocking end moves in the second direction which is substantially rearward. When the latch member is slidably coupled to the actuator, during the movement of the latch toward the intermediate position, the finger actuation portion and the blocking end move in substantially the same direction.
In yet another embodiment, the lighter further includes a biasing element for biasing the latch member into the first position.
In accordance with one aspect of the invention, movement of the latch member toward the intermediate position is caused by a portion of the pulp of a user""s finger that contacts the finger actuation portion.
In accordance with another embodiment, the latch member further includes a body portion with an upper cam surface and a separate cam member. The cam member has the finger actuation portion on the upper surface and a lower cam surface. The cam member is slidably coupled to the body portion such that the lower cam surface contacts the upper cam surface during actuation of the latch member. In accordance with one aspect of this embodiment, in the first position the finger actuation portion is positioned above the outer surface of the actuator and in the intermediate position the finger actuation portion is disposed below the outer surface of the actuator. In accordance with another aspect of this embodiment, the finger actuation portion is below the outer surface of the actuator in the first and intermediate positions.
In yet another embodiment, a lighter comprises a housing, a valve, an actuator and a biased latch member coupled to the actuator. In the first position, the latch member prevents movement of the actuator from the first position to the actuation position. In the intermediate position, the latch member permits movement of the actuator from the first position to the actuation position to ignite the fuel. A user contacts the latch member with a pulp portion of the user""s finger to cause movement of the latch member from the first position to the intermediate position and movement of the actuator from the first position to the actuation position. Upon the user releasing the latch member, the latch member is biased into the first position. The latch member is slidably coupled to the actuator. In another embodiment, the latch member is pivotally coupled to the actuator. In yet another embodiment, the latch member can be slidably or pivotally coupled to a side wall of the actuator.